Species delimitation in poorly known and diverse taxa is usually performed based on monolocus, DNA-­barcoding-­like approaches, while multilocus data are often used to test alternative species hypotheses in well-­studied groups. We combined both approaches to delimit species in the Xenuroturris/Iotyrris complex, a group of venomous marine gastropods from the Indo-P­ acific. First, COI sequences were analysed using three methods of species delimitation to propose primary species hypotheses. Second, RAD sequencing data were also obtained and a maximum-l­ikelihood phylogenetic tree produced. We tested the impact of the level of missing data on the robustness of the phylogenetic tree obtained with the RAD-­seq data. Alternative species partitions revealed with the COI data set were also tested using the RAD-­seq data and the Bayes factor species delimitation method. The congruence between the species hypotheses proposed with the mitochondrial nuclear data sets, together with the morphological variability of the shell and the radula and the distribution pattern, was used to turn the primary species hypotheses into secondary species hypotheses. Allopatric primary species hypotheses defined with the COI gene were interpreted to correspond to intraspecific structure. Most of the species are found sympatrically in the Philippines, and only one is confidently identified as a new species and described as Iotyrris conotaxis n. sp. The results obtained demonstrate the efficiency of the combined monolocus/multilocus approach to delimit species.

ATIMO VATAE, INHACA 2011, MAINBAZA, PAKAIHI I TE MOANA, PAPUA NIUGINI, SANTO 2006, TERRASSES

In shelled molluscs, assigning valid species names to independent evolutionary lineages can be a difficult task. Most original descriptions are based on empty shells and the high levels of variation in shape, color and pattern in some groups can make the shell a poor proxy for species-level identification. The deep-sea gastropod turbinid genus Bolma is one such example, where species-level identification based on shell characters alone is challenging. Here, we show that in Bolma both traditional and molecular taxonomic treatments are associated with a number of pitfalls that can lead to biased inferences about species diversity. Challenges derive from the few phylogenetically informative characters of shells, insufficient information provided in original descriptions and sampling artefacts, which at the molecular level in spatially fragmented organisms can blur distinctions between genetically divergent populations and separate species. Based on a comprehensive dataset combining molecular, morphological and distributional data, this study identified several cases of shell-morphological plasticity and convergence. Results also suggest that what was thought to be a set of distinct, range-restricted species corresponds instead to a smaller number of more widespread species. Overall, using an appropriate sampling design, including type localities, allowed us to assign available names to evolutionarily significant units.

ATIMO VATAE, AURORA 2007, BIOPAPUA, BORDAU 1, CONCALIS, EBISCO, EXBODI, MAINBAZA, MIRIKY, NORFOLK 2, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SALOMONBOA 3, TAIWAN 2004, TERRASSES

Caecidae is a species-rich family of microsnails with a worldwide distribution. Typical for many groups of gastropods, caecid taxonomy is largely based on overt shell characters. However, identification of species using shell characteristics is problematic due to their rather uniform, tubular shells, the presence of different growth stages, and a high degree of intraspecific variability. In the present study, a first integrative approach to caecid taxonomy is provided using light-microscopic investigation with microsculptural analyses and multi-marker barcoding, in conjunction with molecular species delineation analyses (ABGD, haplotype networks, GMYC, and bPTP). In total 132 specimens of Caecum and Meioceras collected during several sampling trips to Central America were analyzed and delineated into a minimum of 19 species to discuss putative synonyms, and supplement the original descriptions. Molecular phylogenetic analyses suggest Meioceras nitidum and M. cubitatum should be reclassified as Caecum , and the genus Meioceras might present a junior synonym of Caecum . Meiofaunal caecids morphologically resembling C. glabrum from the Northeast Atlantic are a complex of cryptic species with independent evolutionary origins, likely associated with multiple habitat shifts to the mesopsammic environment. Caecum invisibile Egger & Jörger, sp. nov. is formally described based on molecular diagnostic characters. This first integrative approach towards the taxonomy of Caecidae increases the known diversity, reveals the need for a reclassification of the genus Caecum and serves as a starting point for a barcoding library of the family, thereby enabling further reliable identifications of these taxonomically challenging microsnails in future studies.

KARUBENTHOS 2012, MADIBENTHOS

In most marine gastropods, the duration of the larval phase is a key feature, strongly influencing species distribution and persistence. Antarctic lineages, in agreement with Thorson's rule, generally show a short pelagic developmental phase (or lack it completely), with very few exceptions. Among them is the ascidian-feeding gastropod family Velutinidae, a quite understudied group. Based on a multilocus (COI, 16S, 28S and ITS2) dataset for 182 specimens collected in Antarctica and other regions worldwide, we investigated the actual Antarctic velutinid diversity, inferred their larval development, tested species genetic connectivity and produced a first phylogenetic framework of the family. We identified 15 Antarctic Molecular Operational Taxonomic Units (MOTUs), some of which represented undescribed species, which show two different types of larval shell, indicating different duration of the Pelagic Larval Phase (PLD). Antarctic velutinids stand as an independent lineage, sister to the rest of the family, with extensive hidden diversity likely produced by rapid radiation. Our phylogenetic framework indicates that this Antarctic flock underwent repeated events of pelagic phase shortening, in agreement with Thorson's rule, yielding species with restricted geographic ranges.

ATIMO VATAE, BIOPAPUA, CEAMARC-AA, PANGLAO 2004, REVOLTA V

Species in the family Capulidae (Littorinimorpha: Capuloidea) display a wide range of shell morphologies. Several species are known to live in association with other benthic invertebrates—mostly bivalves and sabellid worms, but also other gastropods—and are believed to be kleptoparasitic filter feeders that take advantage of the water current produced by the host. This peculiar trophic ecology, implying a sedentary lifestyle, has resulted in highly convergent shell forms. This is particularly true for the genus Hyalorisia Dall, 1889, which occurs in deep water in the Caribbean and Indo-West Pacific provinces, with two nominal species recognized so far. Combining morphological, ecological and molecular data, we assessed the diversity of the genus, its phylogenetic position inside the family and its association with its bivalve host, the genus Propeamussium de Gregorio, 1884 (Pectinoidea), resulting in the description of nine new cryptic species. When sympatric, species of Hyalorisia are associated with different host species, but the same species of Propeamussium may be the host of several allopatric species of Hyalorisia.

AURORA 2007, CONCALIS, CORSICABENTHOS 1, EBISCO, KANACONO, KANADEEP, KARUBENTHOS 2, KAVIENG 2014, KOUMAC 2.3, MADEEP, MAINBAZA, MIRIKY, NanHai 2014, PANGLAO 2004, PANGLAO 2005, SALOMON 2, ZhongSha 2015

Abstract The systematics of the marine mollusc family Velutinidae has long been neglected by taxonomists, mainly because their often internal and fragile shells offer no morphological characters. Velutinids are usually undersampled owing to their cryptic mantle coloration on the solitary, social or colonial ascidians on which they feed and lay eggs. In this study, we address the worldwide diversity and phylogeny of Velutinidae based on the largest molecular dataset (313 specimens) to date, accounting for > 50% of the currently accepted genera, coupled with morphological and ecological data. Velutinids emerge as a diverse group, encompassing four independent subfamily-level lineages, two of which are newly described herein: Marseniopsinae subfam. nov. and Hainotinae subfam. nov. High diversity was found at genus and species levels, with two newly described genera (Variolipallium gen. nov. and Pacifica gen. nov.) and ≥ 86 species in the assayed dataset, 58 of which are new to science (67%). Velutinidae show a remarkable morphological plasticity in shell morphology, mantle extension and chromatic patterns. This variability is likely to be the result of different selective forces, including habitat, depth and trophic interactions.

ATIMO VATAE, BIOMAGLO, BIOPAPUA, CEAMARC-AA, CORSICABENTHOS 1, CORSICABENTHOS 2, CORSICABENTHOS 3, GUYANE 2014, ILES DU SALUT, KANACONO, KANADEEP 2, KARUBENTHOS 2, KAVIENG 2014, KOUMAC 2.1, KOUMAC 2.3, MADEEP, MADIBENTHOS, PANGLAO 2004, PAPUA NIUGINI, SAKIZAYA 2019, SANTO 2006, Tuhaa Pae 2013, ZhongSha 2015

Marginelliform gastropods are a heterogeneous and diverse group of molluscs encompassing over 1,600 living species, among which are the smallest known neogastropods. The relationships of marginelliform gastropods within the order Neogastropoda are controversial, and the monophyly of the two marginelliform families the Marginellidae J. Fleming, 1828 and the Cystiscidae Stimpson, 1865, remains unconfirmed. DNA sequence data have never been used to assess the relationships of the marginelliform gastropods, making this group the only major branch missing in our current understanding of the neogastropod tree of life. Here we report results of the first multilocus phylogenetic analysis of marginelliform gastropods, which is based on a dataset comprising 63 species (20 genera) of Marginellidae and Cystiscidae, and a wide range of neogastropod lineages. The Marginellidae and Cystiscidae form a moderately supported clade that is sister to the family Volutidae. Marginellona gigas appears to be sister to all other marginelliforms. The subfamily Marginellinae was recovered as a well-supported clade, and good resolution of this part of the tree makes it possible to propose amendments to the family-level classification of the group. The relationship between Granulina and other marginelliforms could not be resolved and requires further study. Due to poor resolution of basal relationships within the Marginellidae–Cystiscidae clade, the monophyly of the Cystiscidae was neither confirmed nor convincingly rejected. The shell morphology of most marginellid and cystiscid genera is taxonomically not very informative but, nevertheless, of the traditionally recognized genera only Gibberula and Dentimargo were shown to be polyphyletic. Although a comprehensive systematic revision of the group requires more extensive taxonomic sampling (e.g. with better representation of the type species of nominal genus-group names), our results support the superfamily Volutoidea, comprising four families (Volutidae, Cystiscidae, Marginellidae and Marginellonidae), with the placement of the Granulinidae uncertain for the time being.

ATIMO VATAE, ???msg.security.private???, DongSha 2014, EXBODI, GUYANE 2014, ILES DU SALUT, INHACA 2011, KANACONO, KARUBENTHOS 2, KAVIENG 2014, MADEEP, MADIBENTHOS, MAINBAZA, PAPUA NIUGINI, ???msg.security.private???

Recent expeditions to the China Seas and off Taiwan have resulted in new geographical extensions and new species discoveries in the Muricidae: Abyssotrophon weijencheni n. sp. and Enixotrophon petalospeira n. sp. (Pagodulinae), Scabrotrophon fedosovi n. sp. (Trophoninae) and Siphonochelus hasegawai Houart, Buge & Zuccon, 2021 (Typhinae). A distribution map for each listed species completes the information. Additional information is given for Enixotrophon ziczac (Tiba, 1981) from Japan, not collected during these expeditions but compared with one of the new species described herein.

BATHUS 2, DongSha 2014, KAVALAN 2018, MUSORSTOM 6, TAIWAN 2000, TAIWAN 2001, TAIWAN 2002, TAIWAN 2013, ZhongSha 2015

The classification of the subfamily Typhinae is revised based on a molecular phylogenetic analysis. The genera Typhina Jousseaume, 1880, Typhisopsis Jousseaume, 1880 and Typhisala Jousseaume, 1881 are here treated as synonyms, and Typhina is given precedence over Typhisopsis. Trubatsa Dall, 1889 is confirmed as a separate, valid genus, based on morphological shell characters and molecular analysis. Choreotyphis Iredale, 1936 is also regarded as a valid genus but still requires validation by molecular analysis. An appendix of Recent Typhinae includes a short description of each genus. The list of Typhinae recorded from New Caledonia is updated. The validity of Trubatsa lozoueti (Houart, 1991), a species so far known only from the empty collected holotype, is confirmed by the morphological and molecular analysis of a second specimen.

BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BERYX 11, BIOGEOCAL, CHALCAL 2, CONCALIS, EXBODI, HALIPRO 1, KANACONO, KANADEEP, KOUMAC 2.3, LAGON, LITHIST, MONTROUZIER, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 8, NORFOLK 1, NORFOLK 2, PALEO-SURPRISE, SMIB 3, TERRASSES, VAUBAN 1978-1979

Recent expeditions to the China Seas and off Taiwan have resulted in new geographical extensions and new species discoveries in the Muricidae: Abyssotrophon weijencheni n. sp. and Enixotrophon petalospeira n. sp. (Pagodulinae), Scabrotrophon fedosovi n. sp. (Trophoninae) and Siphonochelus hasegawai Houart, Buge & Zuccon, 2021 (Typhinae). A distribution map for each listed species completes the information. Additional information is given for Enixotrophon ziczac (Tiba, 1981) from Japan, not collected during these expeditions but compared with one of the new species described he

BIOPAPUA, DongSha 2014, KAVALAN 2018, NanHai 2014, PAPUA NIUGINI, TAIWAN 2000, TAIWAN 2002, TAIWAN 2013, ZhongSha 2015

The family Pinnidae Leach, 1819, includes approximately 50 species of large subtidal and coastal marine bivalves. These commercially important species occur in tropical and temperate waters around the world and are most frequently found in seagrass meadows. The taxonomy of the family has been revised a number of times since the early 20th Century, the most recent revision recognizing 55 species distributed in three genera: Pinna, Atrina and Streptopinna, the latter being monotypic. However, to date no phylogenetic analysis of the family has been conducted using morphological or molecular data. The present study analyzed 306 pinnid specimens from around the world, comprising the three described genera and ca. 25 morphospecies. We sequenced the mitochondrial genes 16S rRNA and cytochrome c oxidase subunit I, and the nuclear ribosomal genes 18S rRNA and 28S rRNA. Phylogenetic analysis of the data revealed monophyly of the genus Atrina but also that the genus Streptopinna is nested within Pinna. Based on the strong support for this relationship we propose a new status for Streptopinna Martens, 1880 and treat it as a subgenus (status nov.) of Pinna Linnaeus, 1758. The phylogeny and the species delimitation analyses suggest the presence of cryptic species in many morphospecies displaying a wide Indo-Pacific distribution, including Pinna muricata, Atrina assimilis, A. exusta and P. (Streptopinna) saccata but also in the Atlantic species A. rigida. Altogether our results highlight the challenges associated with morphological identifications in Pinnidae due to the presence of both phenotypic plasticity and morphological stasis and reveal that many pinnid species are not as widely distributed as previously thought.

BIOPAPUA, EXBODI, INHACA 2011, KARUBENTHOS 2012, PAKAIHI I TE MOANA

Bathymodiolinae mussels have been used as a biological model to better understand the evolutionary origin of faunas associated with deep-sea hydrothermal vents and cold seeps. Most studies to date, however, have sampled with a strong bias towards vent and seep species, mainly because of a lack of knowledge of closely related species from organic falls. Here we reassess the species diversity of deep-sea mussels using two genes and a large taxon sample from the South-Western Pacific. This new taxonomic framework serves as a basis for a phylogenetic investigation of their evolutionary history. We first highlight an unexpected allopatric pattern and suggest that mussels usually reported from organic falls are in fact poorly specialized with regard to their environment. This challenges the adaptive scenarios proposed to explain the diversification of the group. Second, we confirm that deep-sea mussels arose from organic falls and then colonized hydrothermal vents and cold seeps in multiple events. Overall, this study constitutes a new basis for further phylogenetic investigations and a global systematic revision of deep-sea mussels. (C) 2010 Elsevier Inc. All rights reserved.

AURORA 2007, BOA1, BORDAU 1, EBISCO, PANGLAO 2005, SALOMON 2, SANTO 2006

Introduction Host-parasite associations provide very useful models to study adaptive processes. We investigated the interaction between carnivorous marine gastropods, the Ovulidae or egg-cowries, and their cnidarian food targets. Ovulidae (Fleming, 1828), is a family of specialized carnivorous caenogastropods that feed by browsing on octocorals (Anthozoa: Octocorallia: Malacalcyonacea and Scleralcyonacea) or, to a much lesser degree, on antipatharians (Anthozoa: Hexacorallia: Antipatharia) and Stylasteridae (Hydrozoa: Hydroidolina: Anthoathecata). Very scanty information is available on the phylogenetic relationships and the degree of specificity of the relationship with the cnidarians of this corallivorous lineage, especially for deep-water taxa. Methods To assess taxonomic identifications and investigate cnidarian/ovulid relationships in the context of their evolution, we generated an extensive molecular dataset comprising two mitochondrial ( cox1 and 16S rDNA ) and one nuclear gene ( 28S rDNA ) from 524 specimens collected worldwide. The coral hosts of the ovulid species have been identified by integrating literature data with new records, employing morphological and/or molecular (the mitochondrial 16S rDNA and mtMSH , and the nuclear ITS2) markers. Results We obtained a molecular phylogenetic framework for the Ovulidae, time-calibrated with nine reliable fossil records. An ancestral state reconstruction allowed to identify Hexacorallia or Hydroidolina as the most likely ancestral cnidarian host for the Ovulidae. Discussion Our phylogenetic hypothesis revealed the existence of groups that do not completely correspond to the currently employed subfamilial arrangement. Concerning trophic ecology, while only pediculariines ( Pedicularia and allied) are associated with hydrozoans (Stylasteridae), our results suggest that some ovulid lineages shifted independently between octocorals and hexacorals.

ATIMO VATAE, AURORA 2007, BIOMAGLO, CORSICABENTHOS 1, CORSICABENTHOS 2, CORSICABENTHOS 3, EBISCO, EXBODI, KANACONO, KANADEEP, KARUBENTHOS 2, KAVIENG 2014, KOUMAC 2.3, MADEEP, MADIBENTHOS, MAINBAZA, MIRIKY, NORFOLK 2, NanHai 2014, PAKAIHI I TE MOANA, PANGLAO 2004, PAPUA NIUGINI, SALOMONBOA 3, SANTO 2006, SPANBIOS, ZhongSha 2015

The subfamily Cantharidinae Gray, 1857 (Trochoidea: Trochidae) includes 23 recognized genera and over 200 known living species. These marine top shell snails are microphagous grazers that generally live in shallow rocky shores and in macroalgae and seagrass beds of sub-tropical and temperate waters from the Central and Western Indo-Pacific biogeographic regions to the Mediterranean Sea and the Eastern Atlantic Ocean. Recent molecular phylogenetic studies revising the family Trochidae supported the monophyly of the subfamily Cantharidinae and its sister group relationship to the subfamily Stomatellinae. These studies and others has thus far mostly focused on Indo-Pacific members of the subfamily Cantharidinae whereas here, we investigated phylogenetic relationships among their counterparts from the Mediterranean Sea and the North-eastern (NE) Atlantic Ocean including 33 species of genera Gibbula, Jujubinus, Phorcus, Clelandella, and Callumbonella. The Mediterranean and NE Atlantic taxa were supplemented with 30 Indo-Pacific Cantharidinae species plus 19 members of the sister group subfamily Stomatellinae. Phylogenetic trees were constructed using Bayesian inference and maximum likelihood with two datasets comprised of partial sequences of four or six mitochondrial (cox1, rrnL, rrnS, and cob) and nuclear (28S rRNA and histone H3) genes. A clade comprised of all Mediterranean and NE Atlantic taxa was recovered with high support, but its sister group among the Indo-Pacific lineages could not be determined with confidence (although the assignment of “Trochus” kotschyi to Priotrochus could be rejected). Within the Mediterranean and NE Atlantic clade, genera Phorcus and Jujubinus were recovered as reciprocally monophyletic, and the deep-sea genera Clelandella and Callumbonella were placed with high support as sister to Jujubinus. However, the genus Gibbula as currently defined was not monophyletic and constituent species were divided into three major clades and two independent lineages. Phylogenetic relationships among Phorcus, Jujubinus (plus Clelandella and Callumbonella), and the different clades of Gibbula were not fully resolved but received higher support in the phylogenetic analyses based on six genes. A first approach to resolve phylogenetic relationships within Stomatellinae was conducted showing that the diversity of the subfamily is highly underestimated at present, and that Calliotrochus is possibly a member of this subfamily. A chronogram was reconstructed using an uncorrelated relaxed lognormal molecular clock and the origin of the Mediterranean and NE Atlantic clade was dated right after the Azolla phase in the Middle Eocene about 48 million years ago whereas diversification of major clades (genera) followed the eastern closure of the Tethys Ocean in the Middle Miocene about 14 million years ago.

ATIMO VATAE, INHACA 2011, PANGLAO 2004, SALOMON 2, SANTO 2006, ???msg.security.private???